fix: remove isInternalAgent flag due to hook ordering race condition

The isInternalAgent flag was causing a race condition where concurrent
internal agents (title/summary generators) would set the flag to true,
and normal session message transforms would see the stale value and skip
injecting the prunable-tools list.

This happened because messages.transform runs before system.transform,
so the flag set by system.transform was always stale by the time
messages.transform checked it.

Fix: Remove the flag entirely and only skip system prompt injection for
internal agents (detected in system.transform where it works reliably).

Author: Tarquinen

index.ts

@@ -37,14 +37,10 @@ const plugin: Plugin = (async (ctx) => {
                 "Summarize what was done in this conversation",
             ]
             if (internalAgentSignatures.some((sig) => systemText.includes(sig))) {
-                logger.info("Skipping DCP injection for internal agent")
-                state.isInternalAgent = true
+                logger.info("Skipping DCP system prompt injection for internal agent")
                 return
             }
 
-            // Reset flag for normal sessions
-            state.isInternalAgent = false
-
             const discardEnabled = config.tools.discard.enabled
             const extractEnabled = config.tools.extract.enabled
 

lib/hooks.ts

@@ -15,7 +15,7 @@ export function createChatMessageTransformHandler(
     return async (input: {}, output: { messages: WithParts[] }) => {
         await checkSession(client, state, logger, output.messages)
 
-        if (state.isSubAgent || state.isInternalAgent) {
+        if (state.isSubAgent) {
             return
         }
 

lib/state/state.ts

@@ -43,7 +43,6 @@ export function createSessionState(): SessionState {
     return {
         sessionId: null,
         isSubAgent: false,
-        isInternalAgent: false,
         prune: {
             toolIds: [],
         },
@@ -63,7 +62,6 @@ export function createSessionState(): SessionState {
 export function resetSessionState(state: SessionState): void {
     state.sessionId = null
     state.isSubAgent = false
-    state.isInternalAgent = false
     state.prune = {
         toolIds: [],
     }

lib/state/types.ts

@@ -27,7 +27,6 @@ export interface Prune {
 export interface SessionState {
     sessionId: string | null
     isSubAgent: boolean
-    isInternalAgent: boolean
     prune: Prune
     stats: SessionStats
     toolParameters: Map<string, ToolParameterEntry>